The Ottomans ruled a vast empire incorporating many different religious and ethnic groups. The Christians and Jews among them, who were regarded in an Islamic context as “the people of the book,” were allowed to appeal to their religious authorities for issues of marriage and divorce. They were also permitted to appeal to the Sharia courts if they so wished. The existence of multiple legal orders created a complex system within the Empire, yet the practical workings of this legal system have rarely been studied. In this context, this dissertation focuses on the institutional practice and family dynamics of Ottoman legal pluralism as evidenced in the registers of the Sharia courts and the Patriarchal court in late seventeenth-century Istanbul. The appearance of non-Muslims in Sharia court registers has led many historians to conclude that non-Muslims widely used the Sharia courts since they were cheaper, more flexible, and more easily accessible, with the decisions of a Muslim judge possessing stronger enforcement power than non-Muslim community courts. This study challenges these assumptions and demonstrates that, at least in issues of divorce and remarriage, Greek Orthodox community members often frequented the Patriarchal court either exclusively or after getting a hüccet (legal writ) from the Sharia courts in order to have the decision of the Muslim judge approved by the Patriarchal synod. Ignoring their return to the Patriarchal court has led some scholars to assume that some Greek Orthodox community members opted for the Sharia court to the exclusion of ecclesiastical courts. Their appeal to the synod despite having an official divorce decree from the Sharia court presents substantial evidence regarding the authority - if not autonomy - and enforcement power of the Church. Despite the seemingly uncompromising attitude of the Church towards coreligionists who turned to the Islamic courts, this study shows that the Church was forgiving of its “unruly” members, a phenomenon indicating the co-dependent nature of their intra-communal relations. In terms of court use practices of Greek Orthodox subjects, this study shows that legal plurality in some cases created an exigency for them to use both courts in view of the different functions they served, rather than a situation of choosing between the two competing and exclusive options in view of their legal interests. Last but not least, this dissertation reveals that Greek Orthodox women were the primary users of the Patriarchal court since the decisions of the synod on some divorce cases were more favorable than the Sharia court rulings. In addition, the synod was for various reasons more lenient towards women. Although some scholars have claimed that Greek Orthodox women found the Sharia courts more suitable because of the option of hul divorce, hüccet references in the Patriarchal court registers and the Sharia court records show that it was predominantly Greek Orthodox men who took advantage of the legal plural system.